All Blacks

McKenzie came off the bench to win his 19th cap in the second half of a 36-34 shock home defeat to South Africa.

The versatile back will not feature when the world champions attempt to show a positive response to that setback against the Pumas in Buenos Aires, though, after it was revealed that he had flown home.

"Damian McKenzie has returned home to New Zealand after a family bereavement," the All Blacks tweeted.

"He will rejoin the All Blacks squad in South Africa. The thoughts of everyone in the All Blacks are with Damian and his family at this sad time."

Moyano is still recovering from a rib injury sustained in the Pumas' victory against Australia on the Gold Coast earlier this month.

Moyano was one of Argentina's standout performers in their 46-24 loss to the All Blacks in Nelson in Round three.

The former Argentina Sevens representative also scored a try in Argentina's 32-19 victory over South Africa in Mendoza last month.

The world champions are six points clear of second-placed South Africa and a win and a bonus point in Buenos Aires on Saturday would guarantee them the trophy.

But after losing at home to the Springboks in their last game they would have their work cut out against an Argentina side who have recorded two wins in the competition for the first time since they joined in 2012, half-back Perenara said.

"We played them in Nelson and we won but it was a tough game," Perenara said.

The All Blacks would have defended the title with two rounds to play had they secured a bonus-point victory, but made a host of uncharacteristic errors as the Springboks withstood a late onslaught to win a Wellington thriller 36-34.

Hansen stated in his post-match news conference that he heard a call saying two South Africa players were offside in the closing stages of a breathless contest.

But the head coach added that referee Nigel Owens would have made the decision had he heard it.

Hansen was responding to comments from former All Black Lima Sopoaga, now playing in England, who says the money on offer overseas will soon outweigh the lure of the All Blacks' jersey.

Hansen doesn't entirely agree, and says New Zealand Rugby isn't at tipping point yet, but insists the current financial model isn't sustainable. He believes if the government and New Zealanders want the All Blacks to remain the best, they would be wise to invest.

The All Blacks became the first team to win back to back World Cups in 2015, cementing their place on World Rugby's throne.

Coach Steve Hansen has made nine personnel changes and a positional switch to his experimental starting team that saw off Argentina 46-24 in Nelson.

A fourth bonus point win from four matches would guarantee a third straight Rugby Championship crown for the world champions with two rounds of matches still to play.

Few would bet against it given the Springboks are coming off successive losses on the road and haven't won in New Zealand for nine years.

It hasn't stopped Hansen naming close to his strongest available team.

The midfielder had scans on his shoulder yesterday and was given the all clear to play after three months on the sidelines.

His return would be timely with Ngani Laumape out injured and Ryan Crotty coming back from concussion.

However the All Blacks assistant coach Ian Foster says Williams was unable to train Tuesday after becoming ill.

"Sonny had a scan yesterday and he's all clear ready to go except he was sick this morning so he didn't train this morning. But the good news is the scan is all clear so now we have just got to get him back on his feet and training.

Shield's made his test debut for England against South Africa in June, but is now in doubt for England's end of year tests including the one against the All Blacks in November.

It was only the Wasps second game of the season.

Shields will see a specialist this week to see if he requires surgery.

Mo'unga replaces the in-form Beauden Barrett in the number 10 jersey for the match against the Pumas and there's no doubt the spotlight will shine brightly on the 24-year-old.

The first-five has been one of the key pieces in the Crusaders' recent Super Rugby success, which has seen the Christchurch side win back-to-back titles.

Read said he'd spoken to Mo'unga privately, and told him to believe in his game and the rest will follow.

Halfback Te Toiroa Tahuriorangi is set to make his Test debut off the bench, while winger Nehe Milner-Skudder returns to the Test side for the first time since October last year.

Milner-Skudder was injured in the All Blacks Test in Cape Town in last year's Rugby Championship and returns on the right wing.

As well as Mo'unga and Tahuriorangi, other back changes in the matchday 23 has TJ Perenara named to start at halfback and Ben Smith move back to fullback.